Every Easter egg from Grey's Anatomy's300th episode

WARNING: This story contains major spoilers from the 300th episode of Grey’s Anatomy. Read at your own risk!

Grey’s Anatomy‘s 300th episode will pay tribute to the 299 that came before it in both big and small ways.

During Thursday’s landmark hour, an accident at a county fair will bring in a variety of patients who spark memories from the doctors’ pasts, including original Fab Five look-alikes Cristina (Sandra Oh), George (T.R. Knight), and Izzie (Katherine Heigl).

As promised, executive producer Krista Vernoff will be hiding quite the Easter egg hunt for long-time fans of the ABC medical drama, from nods to McNames (we presume, because if not? Come on!) to the use of seriously. EW will be taking on the daunting task of gathering every Easter egg from the hour, so be sure to check back! (And if we miss any, hit the comments to help us out!)

Mitch Haaseth/ABC

The 300th episode opened with a version of “Young Folks,” a song first heard in the sixth episode of the third season.

Meredith is riding a ferry boat, which longtime fans know her late husband loved.

The new class of interns is seen camped out in the tunnel that the Fab Five previously called home, with “Glasses” even tripping like George did in the pilot when they get a page. They subsequently run across the catwalk, where Meredith and Alex are telling them to slow down — something they were once told to do back in the pilot.

Two of the roller coaster accident patients look like George and Cristina, with a third looking like Izzie, who exclaims “seriously,” a common word used in the early seasons. The three are actually second-year residents at Seattle Presbyterian.

The paramedics who bring in the roller coaster crash patients, Nicole and Ray, have both appeared in many episodes of the show.

The opening scene ended with the show’s original theme song, “Cosy in the Rocket,” by Psapp.

Amelia pushes for a head CT on a patient. Her brother Derek ultimately died because his doctors didn’t do a head CT. When Owen declines to do it, Amelia pushes for it to happen during the surgery and ends up being right.

During the episode “Into You Like a Train,” the patients were stuck together via a pole and the doctors could not remove one without risking injury to the other, much like these George and Cristina look-alikes.

Jo says “seriously” while Alex is showing her the Izzie look-alike.

The episode utilizes another old song, “They,” by Jem.

The George look-alike is shocked to discover that George died a hero. For those who forgot, just after enlisting in the Army, George was hit by a bus while saving a woman.

The Izzie look-alike asks Alex to stay by her side, which is dangerously similar to how close he got to Rebecca following the ferry crash. (When “Izzie” passed out, Alex carried her like he did after Denny died.)

The Cristina look-alike calls Meredith and Jackson surgeon royalty, which is what her fellow interns said of Meredith’s mom in the pilot.

When one of the interns goes to Dr. Shepherd, mentioning the patient’s family is there, it’s a line verbatim from the pilot.

Though she’s about to go into surgery, the Izzie look-alike is as positive as ever, bringing up the silver linings — something the real Izzie always did.

DeLuca and one of the new interns, with whom he has a past, hook up in an on-call room.

Meredith mentions that Cristina Yang, of all people, would know how badly she would want to win a Harper Avery. Yes, so badly that Cristina left Grey Sloan in order to be able to win one.

When asked about Sofia’s father, Arizona mentions he’s dead — Mark Sloan died following the plane crash — and then does a spot-on impression of him.

When Maggie says Zola must get her intelligence from her mother, Zola says it comes from her dad, too, whom she misses. RIP Derek.

While working on the George look-alike, Webber mentions it will be nice to save this O’Malley — George died just after the doctors discovered they were working on their fellow doctor. RIP 007!

Even though Alex hasn’t spoken to Izzie in years, he’s imagined that she’s married with kids, living somewhere woodsy, her house smells like muffins, and she’s happy. He doesn’t want to call her, because he doesn’t want that vision to be shattered.

Because Meredith didn’t make it to the Harper Avery Awards, Webber and Bailey set up a video feed so Meredith could find out she won. As she’s watching the feed, she looks up to see her late mother — the returning Kate Burton as Ellis Grey — in the OR gallery. In addition to mentioning Ellis during his speech, Jackson also brings up the losses of Meredith’s sister, Lexie (Chyler Leigh), and Meredith’s husband, Derek.

When Owen disagreed about the Cristina look-alike sharing any resemblance to his former wife, Meredith jokingly said she should send a photo to Burke (Isaiah Washington), Cristina’s other ex and another original character, to get his opinion.

Upon returning home, Sofia mentions missing her mom, Callie (Sara Ramirez). Arizona gives her three different flavors of ice cream, something Mark had previously mentioned. And then there’s a photo of Callie, Arizona, and Mark shown on the wall.

One of the final songs is Rilo Kiley’s “Portions for Foxes,” which is the first song played in the pilot.

Alex and Meredith return to the tunnel, where Meredith gets a call from Cristina.